Electric plug and socket connectors



INVENTOE ATTQRNEY;

C. W. CLARK ELECTRIC PLUG AND SOCKET CONNECTORS Filed Nov. 19, 1963 May17, 1966 M/d W Q Q 9 P9 S United States Patent 3,252,128 ELECTRIC PLUGAND SOCKET CONNECTORS Charles William Clark, Penn, England, assignor t0C.W.C. Equipment Limited, Maidenhead, England, a company of GreatBritain Filed Nov. 19, 1963, Ser. No. 324,636 Claims priority,application Great Britain, Nov. 23, 1962, 44,479/ 62 4 Claims. (Cl.339-217) This invention relates to electrical plug and socket connectorsand is concerned with the socket assemblies of such connectors of thekind in which, owing for example to the high temperatures to which theassembly may be subjected in use (e.g. in aircraft), the metallic socketmember or each of a number of such socket members which are mounted inan insulating body and are to cooperate with one or more plug membersmounted in a second insulating body, has to be attachable to the end ofits associated insulated electric cable by crimping, that is to say bydeforming a part of the socket member surrounding a bore into which theend part of the electric cable projects so that such end part is firmlyheld within and in intimate electrical contact with such part of thesocket member, as opposed to soldering the conducting cable to thesocket.

In many cases it is also a requirement that the socket assembly as awhole shall withstand a pressure difference between the front face intowhich the plug or plugs are inserted and the back face from which theconducting cable or cables attached to the socket member or membersextend, while moreover a large degree of reliability and a very lowmillivolt drop across the plug and socket connection when in use isrequired.

Further, the socket members are preferably supported in their insulatingbody in a manner providing for a degree of flexibility to ensure propermating with the plug members with which they are to co-operate.

It is an object of the invention to provide an improved form of socketassembly which will meet some or all the above requirements to asatisfactory degree.

A socket assembly of the kind referred to according to the presentinvention comprises a body of insulating material, at least one boreextending through the body, and a conducting socket member which extendswithin the bore and comprises tubular end parts one of wh ch liesadjacent to one of the open ends of the bore and is formed forengagement by a contact pin of a co-operating plug member while theother is formed to receive the end portion of an insulated electriccable and an intermediate part which lies between the two tubular endparts and has a relatively small diameter bore to receive an end portionof the conducting cable, the tubular end part which is formed to receivethe insulated cable including also an external flange or projectionwhich lies within a corresponding recess in the body of insulatingmaterial so as to serve normally to maintain the socket member withinthe bore and being slotted longitudinally to provide for resilientradial inward displacement of the parts between the slots and having anexternally tapered end portion for engagement with the bore of anextraction tool which can be inserted through the adjacent end of thebore of the insulating body to cause such inward radial displacement andthus reduce the effective external diameter of the flange or projectionto permit withdrawal of the socket member bodily from the bore in theinsulating body.

Preferably the flange has a frusto-conical face, the circumferentialgroove in which it lies has a corresponding cooperating frusto-conicalface and a resilient sealing washer is interposed between these twofaces to form a fluid-tight seal around the socket member.

The intermediate part is preferably formed so that it can be plasticallydeformed as by crimp ng to secure the end of the conducting cabletherein.

The invention also consists in an electrical socket element for apin-and-socket electrical connection, having a tubular formation at oneend, which is slotted lengthwise to permit radial inward displacement ofthe wall of the tubular formation, the said tubular wall being formedwith external projections which serve as anchorages when the wall partsare splayed outwards. The tubular formation will preferably be formedwith an external taper, so that a tubular tool driven over'the end ofthe tubular formation will deform the wall parts inwards.

Preferably, while the slotting in the end of the tubular part throughwhichthe electric cable is to pass extends to the end of the part, theslotting at the end of the tubular part which is intended for entry ofthe cooperating plug member does not extend to the end of that part,thus leaving a complete ring of metal through which the plug passes intothe slotted part.

A construction of socket assembly according to the invention is shown byway of example in the accompanying drawings, in which FIGURE 1 is a sideelevation partly in cross-section of a complete socket assemblyincluding a number of sockets of which the only one which appears isshown for convenience in side elevation,

FIGURE 2 is a sectional side elevation on an enlarged scale of a socketas incorporated in the assembly shown in FIGURE 1 but before theattachment of such socket to an insulated electrical conductor, and

FIGURE 3 is a sectional side elevation on the same scale as FIGURE 2showing in detail the form of the socket when lying within itsassociated body of moulded insulating material and attached to the endof an insulated conductor, that is to say the general form andarrangement which each of the sockets in the assembly shown in FIGURE 1would have when incorporated in that assembly, FIGURE 3 also includingpart of a withdrawing tool for use with such assemblies. v

In the construction shown in the drawings the assembly comprises a bodyof moulded insulating material consisting of two mouldings =1 and 2secured face to face within a metallic housing 3 by means of ascrewthreaded clamping ring 4 which has a flange 5 bearing on the outerface of the part 2 so that the parts 1 and 2 are clamped togetherbetween the flange 5 and an internal flange 6 formed in the housing 3and engaged by a shoulder on the part 1. The body of moulded insulatingmaterial thus constituted by the two mouldings 1 and 2 is formed toprovide a number of cylindrical bores of which one is shown at 7, thesebores being spaced from one another within the body of insulatingmaterial in a manner cornmon for socket assemblies of the character inquestion and containing sockets constructed and arranged as hereinafterdescribed for cooperation with the pins of an associated plug assem bly(not shown) which, after the pins have been inserted into the sockets,can be ecured to the socket assembly by a clamping ring shown at 8 inconventional manner.

The general form of each of the sockets which lies within one of thebores 7 is shown in FIGURES Z and 3, g I

As will be seen more particularly from FIGURE 3, each of the bores 7 isprovided adjacent to the joint face between the parts 1 and -2 with acircumferential groove having one radial face 9 and one frusto-conicalface 10, a thin trusto-conical sealing washer 11 extending over thefrustoconical face 10 -and having formed integral with it a tubularextension 11a lying within a slightly enlarged portion of the bore inthe part 1 as shown. Mounted within the bore 7 is a metallic one piecesocket member which comprises a cireumferentially complete tubular endpart 12 having a bore of slightly greater diameter than the externaldiameter of the pin which will enter it when a plug assembly is appliedto the socket assembly, a tubular part 13 lying adjacent to the-part 12having a bore slightly less than that of the part 12 and iormed with aseries of longitudinally extending circumferentially spaced slots 13a sothat the part 13 consists in efliect of a series of spaced bars givingto it a degree of radial resilience so that when a pin is pressed intoit it will grip the pin and make a good electrical contact therewith ina manner generally known per se, the end of the part .13 remote from thepart 12 of the socket being provided with a body part 14 having a boreconsiderably smaller in diameter than the bore of the part 12 andintended to receive the end of an electric conductor 15 as indicated inFIGURE 3 while the end of the socket member remote from the part 1 2 hasa bore 16 of a diameter suitable for accommodating the insulatingcovering 15a with which the conductor 15 is covered except where itprojects from the end of such covering as shown in FIGURE 3.

In addition the end of the socket member re'mote firom the part 12 isprovided with a series of circumferentially spaced slots 17 so that itconsists in eflect of a series of fingers 17a and with an externalflange or projection 18 through which the slots 17 also extend, theflange 18 being appropriately dimensioned for accommodation within thegroove 9, 10 in the bore 7 as shown in FIGURE 3.

As mentioned above, FIGURE 2 shows the form of a socket member beforeits attachment to an insulated electric conductor, while FIGURE 3 showsthe socket member after such attachment. The method of attac ment is asfollows: An appropriate length of the insulating covering 15a of theconductor 15 having been removed so as to expose the end portion of theconductor 15 which is to be electrically connected to the socket member,this end portion and the adjacent part of the insulating covering arepushed into the righthand end of the socket member shown in FIGURE 3 sothat the bare end of the conductor 15 enters the bore in the part 14 andthe adjacent part of the insulating covering enters the bore 16 so assubstantially to fill that bore. The part 14 is now deformed by crimpingas shown at 14a in FIGURE 3, while the parts of the socket memberimmediately adjacent to the ends of the slots 17 are deformed as shownat 16a in FIGURE 3 so that the end of the conductor 15 is firrnlygripped within the 'bore of the part 14 While 7' the end of theinsulating covering 15a is-held within the lefthand end of the bore 16.It will be understood that the metal of which the socket member isfiormed is such as to allow for the crimping and deformation referredto.

When each of the sockets incorporated in the socket assembly shown inFIGURE 1 has thus been attached to the end of its associated insulatedelectric conductor, these socket members are pressed into place withinthe bores 7 from the righthand ends of such bores. operation, when thefrusto-conical surface of the flange 18 reaches the ri-ghthand end ofthe bore 7 suflicient pressure may be applied to the socket to cause thefingers 17a to be forced inwards so as to reduce the effective diameterDuring this of the flange 18 and allow the flange 18 to pass into andthrough such righthand end of the bore 7 until the flange 18 reaches thecircumferential recess 9, 10, whereupon the fingers 17a spring outwardsso that the socket member is held in position. Alternatively the fingers17a. may be pressed inwards by a tool such as the withdrawing toolhereinafter referred to, to facilitate or permit the passage of theflange 18 through the ri-ghthand end of the bore 7. Each socket member,therefore, after insertion into its bore 7 is in the form and occupiesthe position indicated in FIGURE 3. It will be seen that, when thesocket member occupies the position shown in FIGURE 3, the end portionof the part 11a lies closely around the adjacent portion of the bodypart 14 so as to form a seal between this portion of the body part andthe wall of the bore 7.

If a socket member is to be withdrawn from the assembly, this can beeflected by means of a withdrawing tool one end of which is shown at 19in FIGURE 3, this withdrawing tool having, as shown, a tubular end whichis freely slidable into the bore 7 around the insulated covering a andhas at the end of its bore a frusto-coni'cal part 20 which co-operateswith a corresponding trustecon-ical part 17 b on the adjacent end of thesocket member to press the fingers 17a inwards and thus reduce theeifective diameter of the flange 18 to a point where this flange can bewithdrawn through the righthand end of the bore 7.

It will be understood that when the withdrawing tool is being used inthis way an appropriate pressure will be applied to the lefthand end ofthe socket member to prevent its being forced to the left as theeifective diameter of the flange 18 is being reduced, and to force it tothe right when that diameter has been reduced by the tool 19 to a pointwhere the flange 18 can pass through the righthand end of the bore 7.It'will also be understood that the end portion 19 of the tool will beformed in two semicylindrical parts to enable it to be assembled aroundthe insulating covering 15a prior to insertion into the bore 7 as shownin FIGURE 3.

What I claim as my invention and desire to secure by Letters Patent is:

1. An electrical socket assembly for co-cperation with a plug assembly,comprising a body of insulating material, at least one bore extendingthrough the body and a conducting socket member which extends within thebore and comprises tubular end parts one of which lies adjacent to oneof the open ends of the bore and is formed for engagement by a contactpin of a (Io-operating plug member while the other is formed to receivethe end portion of an insulated electric cable and an intermediate part,which lies between the two tubular end parts and has a relatively smalldiameter bore to receive an end portion of the conducting cable, thetubular end part which is formed to receive the insulated cableincluding also an external flange or projection which lies within acorresponding recess in the body of insulating material so as to servenormally to maintain the socket member within the bore and being slottedlongitudinally to provide for resilient radial inward displacement ofthe parts between the slots and having an externally tapered end portionfor engagement with the bore of an extraction tool which can be insertedthrough the adjacent end of the bore of the insulating body to causesuch inward radial displacement and thus reduce the effective externaldiameter of the flange or projection to permit withdrawal of .the socketmember bodily from the bore in the insulating body.

3,252,128 5 6 4. An electrical socket assembly as claimed in claim 3,References Cited by the Examiner in which the end portion of the socketmember into which UNITED STATES PATENTS the electrical conducting cab-1eextends has a larger bore formed to receive an electric conduct-in cablewith its 2685073 7/1954 Damon 339 217 g 2 911 6 12 11/1959 Jackson et a13'39217 X insulating covering from the inner end of which langer 53:026496 3/1962 Gluck 339 217 bo're opens a smaller bore to receive apart of the eonduct- 3172:721 3/1965 Kelly ing cable without insulatingcovering, parts of the socket surrounding the large bore beingplasticailly deformed or SEPH D. SEERS, Prima y Ex miner. deformable togrip said insulating covering. 10 CLIFFORD, Assistant Examiner

1. AN ELECTRICAL SOCKET ASSEMBLY FOR CO-OPERATION WITH A PLUG ASSEMBLY,COMPRISING A BODY OF INSULATING MATERIAL, AT LEAST ONE BORE EXTENDINGTHROUGH THE BODY AND A CONDUCTING SOCKET MEMBER WHICH EXTENDS WITHIN THEBORE AND COMPRISES TUBULAR END PARTS ONE OF WHICH LIES ADJACENT TO ONEOF THE OPEN ENDS OF THE BORE AND IS FORMED FOR ENGAGEMENT BY A CONTACTPIN OF A CO-OPERATING PLUG MEMBER WHILE THE OTHER IS FORMED TO RECEIVETHE END PORTION OF AN INSULATED ELECTRIC CABLE AND AN INTERMEDIATE PART,WHICH LIES BETWEEN THE TWO TUBULAR END PARTS AND HAS A RELATIVELY SMALLDIAMETER BORE TO RECEIVE AN END PORTION OF THE CONDUCTING CABLE, THETUBULAR END PART WHICH IS FORMED TO RECEIVE THE INSULATED CABLEINCLUDING ALSO AN EXTERNAL FLANGE OR PROJECTION WHICH LIES WITHIN ACORRESPONDING RECESS IN THE BODY OF INSULATING MATERIAL SO AS TO SERVENORMALLY TO MAINTAIN THE SOCKET MEMBER WITHIN THE BORE AND BEING SLOTTEDLONGITUDINALLY TO PROVIDE FOR RESILIENT RADIAL INWARD DISPLACEMENT OFTHE PARTS BETWEEN THE SLOTS AND HAVING AN EXTERNALLY TAPERED END PORTIONFOR ENGAGEMENT WITH THE BORE OF AN EXTRACTION TOOL WHICH CAN BE INSERTEDTHROUGH THE ADJACENT END OF THE BORE OF THE INSULATING BODY TO CAUSESUCH INWARD RADIAL DISPLACEMENT AND THUS REDUCE THE EFFECTIVE EXTERNALDIAMETER OF THE FLANGE OR PROJECTION TO PERMIT WITHDRAWAL OF THE SOCKETMEMBER BODILY FROM THE BORE IN THE INSULATING BODY.